Video Calls for External Networks

1. A method for setting up a video communication session via an Internet Protocol (IP) network between a first correspondent and a second correspondent, the method having the steps of: providing a call server on an IP network, said call server configured to facilitate said video communication session between said correspondents; assigning a unique identifier to each of said correspondents; registering said unique identifier and at least one attribute associated with each of said correspondents with said call server; said first correspondent placing a call through a public switched telephone network (PSTN) to said second correspondent to establish a PSTN communication session, and said first correspondent simultaneously initiating a set-up procedure for a video communication session by sending a request to said call server to determine whether said second correspondent is registered with said call server; and when said second correspondent is registered with said call server determining whether said second correspondent is compatible with said first correspondent based on at least one attribute; when said second correspondent is compatible with said first correspondent, said call server sending a video communication session invitation to said second correspondent via said IP network; and when second correspondent accepts said invitation, establishing said video communication session via said IP network between said first correspondent and said second correspondent, wherein said video communication session is established via said call server.

2. The method of claim 1 wherein said PSTN communication session is terminated upon establishment of said video communication session.

3. A method for setting up a video communication session an Internet Protocol (IP) network between a first correspondent and a second correspondent, the method having the steps of: providing a call server on an IP network, said call server configured to facilitate said video communication session said correspondents; assigning a unique identifier to each of said correspondents; registering said unique identifier and at least one attribute associated with each of said correspondents with a directory on said IP network; said first correspondent placing a call through a public switched telephone network (PTSN) to said second correspondent to establish a PSTN communication session, and said first correspondent simultaneously initiating a query to said directory to determine said at least one attribute of said second correspondent, and to determine whether said second correspondent is compatible with said first correspondent based on at least one attribute; when said second correspondent is compatible with said first correspondent, one of said correspondents initiating a video communication session via said call server; and said call server assigning a unique video communication session identifier and establishing said video communication session via said IP network between said correspondents.

4. The method of claim 3 wherein said directory is an E. 164 directory.

5. The method of claim 4 wherein said query to said directory is sent via said IP network.